Matlab (3) matlab program flow control statement

Sequential structure

if sentence

MATLAB Of if Statements and C Language similarity , The difference lies in ：

1. else and if There is no space between
2. The expression does not need brackets "(“ and ”)" Cover up
3. Keyword is required at the end end Express
4. Statement groups do not need braces "{" and “}” Cover up （ Because there will be end as well as else And other keywords ）

Examples are as follows

if  expression 
   Statement group 
elseif  expression 2
   Statement group 2
else
   Statement group 3
end

The structure flow control statement is in m Files and command line windows can be written , When writing in the command line window , The lower left corner will show “ Continue entering statements ” The words... , Until input end And press enter , Will start to execute .

switch sentence

MATLAB Of switch Statements and C Language similarity , The difference lies in ：

1. The final default option is otherwise instead of default
2. case No colon is required after the statement ":"
3. case The constant expression in the statement can be an array （ Using array names 、{} The enclosed elements are ok ）
4. Keyword is required at the end end Express
5. case Statement groups do not need braces "{" and “}” Cover up

Examples are as follows

switch  expression 
  case  Constant expression 1
        Statement group 1
  case  Constant expression 2
        Statement group 2
  default
        Statement group 3
end

MATLAB Of switch Unwanted break, Instead, execute any statement group and exit .

Loop structure

for sentence

       MATLAB Of for Examples of statements are as follows

for  Loop variable = Array expression 
   The loop body 
end

        among , Array expressions can use array names , At this time, in each cycle , The cyclic variable is equal to the element corresponding to the subscript . Of course , Generally, colon expression can also be used as array expression ,C Linguistic for(num=0;num<10;num++) And MATLAB Of for num=0:1:9 equivalent , Of course , Personal feeling C Linguistic for Sentences are more flexible ,（ After all, conditions are easier to write , And the elements corresponding to subscripts can be used in arrays in the loop body ）, Of course ,MATLAB Of for Statements can also implement C Functions in language .（ Add a judgment at most and break）

while sentence

       MATLAB Of while Examples of statements are as follows , And C The language is as like as two peas. .（ But expressions don't need parentheses ）

while  expression 
   The loop body 
end

Other statements

break

        Generally used in loop statements , Used to terminate the innermost loop .

continue

        Generally used in loop statements , Used to skip this loop .

return

        Make the executing function exit normally

try…catch…

Format ：

try
   Statement group 1
catch
   Statement group 2
end

       try…catch… The statement is actually the same as the following if The structure is similar to , Execute statement group 1, If there is an error, execute the statement group 2.（ If normal, do not execute the statement group 2, It's skipping ）

if ! Statement group 1
   Statement group 2
end

       try…catch… The use of can improve the fault tolerance of the program and the flexibility of program design , Instead of jumping to the dead cycle or stopping operation when encountering errors .